Performance and Mass vs. Operating Temperature for Pulse Tube and Stirling Cryocoolers
Single stage pulse tube and Stirling cryocooler data that were reported in the open literature during the past decade were analyzed to find mathematical scaling laws for estimating the required input power and mass, as functions of the operating temperature at a required capacity, for ambient temperature heat rejection. It is found that the average fraction of Carnot efficiency, determined empirically from an abundance of performance data for each cooler type, follows a relatively smooth nonlinear curve when plotted against the cold head operating temperature. This result can be used to estimate the required input power for a given temperature and capacity requirement. Incorporating results from a previous survey that separately tabulated the cryocooler electronics and thermomechanical masses of many space cryocoolers, the cryocooler total mass can be estimated from the input power requirement using equations derived from the survey results.